Iain Morrison won 15 caps for Scotland between 1993 and 1995 including three appearances at the 1995 Rugby World Cup in South Africa. He currently works for the Scotland on Sunday newspaper and has been a regular contributor to Scrum.com since 1999.

So, the Scotland Rugby World Cup Squad. I have to take off my shoes and socks just to count to 20, but even I know that you can't squeeze 40 into 30. Instead Andy Robinson will have to shed 10 members of his current squad before handing the remainder a club class ticket to New Zealand for the big one in September.

Let's presume for a moment that Robinson does what most coaches do and takes three scrummies and three hookers - it seems sensible and he has already pretty much admitted as much. The hookers are easy: Ross Ford, Scott Lawson and Dougie Hall, with Fergus Thomson missing out.

The second-row is even easier given that just four locks are included in the extended squad. Al Kellock, Richie Gray, Nathan Hines and Jim Hamilton will travel.

It's a different picture in the back-row, where Robinson has named eight and he will probably take six. Kelly Brown and John Barclay are sure things, home runs. David Denton is one to watch but he has enjoyed just seven starts for Edinburgh so he is probably there to give Johnny Beattie hurry up. The Glasgow No.8 was injured for much of the season but he is a favourite of Robinson and a man who usually rises to the big occasion.

Alasdair Strokosch will travel because he offers a hard, uncompromising edge that chimes with the coach, while Richie Vernon and Ross Rennie will make up the six with the uncapped Rob Harley the other unlucky flanker.

There are just two fly-halves in the squad, Ruaridh Jackson and Dan Parks, so both will make it, with back up coming from Greig Laidlaw/Chris Paterson.

In the midfield, Graeme Morrison is a certainty and Joe Ansbro's pace and versatility ensure his place. Nick De Luca has had a poor season but he can play 12 or 13 and he should go, with Sean Lamont offering additional back up at inside-centre and Max Evans doing the same one place wider. Those last two will travel as back-three picks along with Simon Danielli, Rory Lamont and Paterson (Nikki Walker and Hugo Southwell are left hoping for an injury).

All the above is relatively simple - although not to be confused with being right - and leaves just two positions where Robinson has a genuine dilemma...scrum-half and prop. Here's the thinking...

Chris Cusiter was Robinson's first choice No.9 and an old favourite. He is in Australia getting some much needed game time after almost a year out and, provided he returns from Oz in one piece he will go. So too will Rory Lawson, who has never let anyone down. His kicking game is excellent and his pass the best of all, an important consideration when Jackson needs every extra split second he can get.

So Robbo must send a "Dear John" letter to one of the two remaining scrum-halves. Mike Blair has 71 Test caps while Greig Laidlaw has exactly one, but the latter still has a fighting chance of seeing New Zealand in September.
At his best Blair is world class but we haven't seen his best since the Edinburgh man was nominated for the IRB Player of the Year award in 2008.

Laidlaw started more games for Edinburgh this season than his rival and he brings versatility which is important given the restrictions on numbers. Laidlaw is equally comfortable in either halfback position, indeed he started a couple of times for Edinburgh in the 10 shirt at the tail end of the season, and crucially he kicks goals.

Jackson is unreliable in front of posts so when Robinson's favoured fly-half starts, Chris Paterson is usually to be found at fullback to ensure that penalties mean points. With the pace and power of Rory Lamont set to come on at No.15 late in the game, Robinson might then want to throw Laidlaw on at scrum-half to ensure Scotland still kick their penalties. Blair v Laidlaw is too close to call, but if Robinson is going on form rather than history the one cap wonder should get the chance to add to that tally.

The coach's other headache is at the coal-face, where Allan Jacobsen, Euan Murray and Geoff Cross should travel - leaving Ally Dickinson and Moray Low fighting it out for the final prop position. Admittedly, Low is a tight-head by trade but both he and Cross have filled in on the loose and could do so again. Dickinson's scrummaging at the highest level is suspect.

Low got the better of the Pumas last summer, but he hasn't got the better of anyone else since. Ryan Grant is much improved this year but without any international experience he would be a huge risk and Robbo will probably go with the devil he knows in Dickinson.

He will also keep his fingers crossed that Allan "Chunk" Jacobsen's World Cup is longer than it was last time out, when he lasted 20 minutes against Portugal in before tearing his calf.

In what is sure to be a hugely physical, bruising contest, that gives Scotland a 17/13 split with good cover all round and only a shortage of world class - proven match winners like Brian O'Driscoll - holding this squad back. What's the latest news on cloning?